Absolute isotopic composition and atomic weight of erbium

Calibrated mass spectrometric measurements on highly enriched isotopes of erbium in the form of oxides of well-defined purity were carried out by using a thermal ionization mass spectrometer, yielding an absolute isotopic composition of 0.139(3) at. % Er-162, 1.601(2) at. % Er-164, 33.503(24) at. % Er-166, 22.869(6) at. % Er-167, 26.978(12) at, % Er-168, and 14.910(24) at. % Er-170, and the atomic weight of erbium as 167.2591(9) with an uncertainty given on the basis of 95% confidence limit. No isotopic fractionation was found in terrestrial normal erbium materials. (Int J Mass Spectrom 177 (1998) 131-136) (C) 1998 Elsevier Science B.V.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000076156900004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, Atomic, Molecular & ChemicalSpectroscopySCI(E)18ARTICLE2-3131-13617